xref: /freebsd/sys/dev/uart/uart_dev_ti8250.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2013 Ian Lepore
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "opt_platform.h"
30 
31 #include <sys/cdefs.h>
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/conf.h>
36 #include <sys/kernel.h>
37 #include <sys/sysctl.h>
38 #include <machine/bus.h>
39 
40 #include <dev/fdt/fdt_common.h>
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 
44 #include <dev/uart/uart.h>
45 #include <dev/uart/uart_cpu.h>
46 #include <dev/uart/uart_cpu_fdt.h>
47 #include <dev/uart/uart_bus.h>
48 #include <dev/uart/uart_dev_ns8250.h>
49 
50 #include <arm/ti/ti_sysc.h>
51 
52 #include "uart_if.h"
53 
54 /*
55  * High-level UART interface.
56  */
57 struct ti8250_softc {
58 	struct ns8250_softc ns8250_base;
59 	/*uint32_t	mystuff;*/
60 };
61 
62 #define	MDR1_REG		8
63 #define	  MDR1_MODE_UART	0
64 #define	  MDR1_MODE_DISABLE	7
65 #define	SYSCC_REG		15
66 #define	  SYSCC_SOFTRESET	(1 << 1)
67 #define	SYSS_REG		16
68 #define	  SYSS_STATUS_RESETDONE	(1 << 0)
69 
70 static int
71 ti8250_bus_probe(struct uart_softc *sc)
72 {
73 	int status;
74 
75 	if ((status = ti_sysc_clock_enable(device_get_parent(sc->sc_dev))) != 0)
76 		return (status);
77 
78 	/*
79 	 * Set the hardware to disabled mode, do a full device reset, then set
80 	 * it to uart mode.  Most devices will be reset-and-disabled already,
81 	 * but you never know what a bootloader might have done.
82 	 */
83 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_DISABLE);
84 	uart_setreg(&sc->sc_bas, SYSCC_REG, SYSCC_SOFTRESET);
85 	while (uart_getreg(&sc->sc_bas, SYSS_REG) & SYSS_STATUS_RESETDONE)
86 		continue;
87 	uart_setreg(&sc->sc_bas, MDR1_REG, MDR1_MODE_UART);
88 
89 	status = ns8250_bus_probe(sc);
90 	if (status == 0)
91 		device_set_desc(sc->sc_dev, "TI UART (16550 compatible)");
92 
93 	return (status);
94 }
95 
96 static kobj_method_t ti8250_methods[] = {
97 	KOBJMETHOD(uart_probe,		ti8250_bus_probe),
98 
99 	KOBJMETHOD(uart_attach,		ns8250_bus_attach),
100 	KOBJMETHOD(uart_detach,		ns8250_bus_detach),
101 	KOBJMETHOD(uart_flush,		ns8250_bus_flush),
102 	KOBJMETHOD(uart_getsig,		ns8250_bus_getsig),
103 	KOBJMETHOD(uart_ioctl,		ns8250_bus_ioctl),
104 	KOBJMETHOD(uart_ipend,		ns8250_bus_ipend),
105 	KOBJMETHOD(uart_param,		ns8250_bus_param),
106 	KOBJMETHOD(uart_receive,	ns8250_bus_receive),
107 	KOBJMETHOD(uart_setsig,		ns8250_bus_setsig),
108 	KOBJMETHOD(uart_transmit,	ns8250_bus_transmit),
109 	KOBJMETHOD_END
110 };
111 
112 static struct uart_class uart_ti8250_class = {
113 	"ti8250",
114 	ti8250_methods,
115 	sizeof(struct ti8250_softc),
116 	.uc_ops = &uart_ns8250_ops,
117 	.uc_range = 0x88,
118 	.uc_rclk = 48000000,
119 	.uc_rshift = 2
120 };
121 static struct ofw_compat_data compat_data[] = {
122 	{"ti,ns16550",		(uintptr_t)&uart_ti8250_class},
123 	{"ti,omap3-uart",	(uintptr_t)&uart_ti8250_class},
124 	{"ti,omap4-uart",	(uintptr_t)&uart_ti8250_class},
125 	{NULL,			(uintptr_t)NULL},
126 };
127 UART_FDT_CLASS_AND_DEVICE(compat_data);
128